Centrifugal spreader



H. DR EYER CENTRIFUGAL SPREADER Feb. 13, 3968 Filed May 11, 1965 INVENTOR HEINZ DREYER aw M ATTORNEYS.

United States Patent 3,368,762 CEGAL SPREADER Heinz Dreyer, Osnabruck, Germany, assignor t0 Amazonen-Werke H. Dreyer, Kreis Osnabruck, Germany, a corporation of Germany Filed May 11, 1965, Ser. No. 455,013 5 Claims. (Cl. 239-665) ABSTRACT OF THE DISCLOSURE A centrifugal spreader having a pair of rotatable disks each bearing one or more slinger elements and positioned side-by-side for rotation within a common horizontal plane to spreadingly dispense by centrifugal action granular material introduced onto their upper surfaces, each disk and its slinger elements defining a centrifugal scattering member. The two centrifugal scattering members have maximum radial dimensions which total in excess of the spacing between their rotation centers, and their disk peripheral contours are so shaped, and their slinger elements are so arranged as to allow partsof each scattering member to extend into the path swept by the other without interference when the two scattering members are rotated in synchronism.

This invention relates in general to centrifugal spreaders for dispensing granular materials, such as mineral fertilizers, and more particularly to a centrifugal spreader in which the granular material to be spreadingly dispensed is supplied onto a pair of rotating elements which spreadingly dispense the granular material therefrom by centrifugal action.

These centrifugal dispensing elements rotate in respective paths that are fixed in relation to each other and partially overlap, and are supported for such rotation by any suitable conventional base means, such as a vehicle platform.

The same base means can be advantageously used to support the means for rotatably driving the centrifugal dispensing elements, and as well, the means, such as a hopper, which-is used to supply the granular material to said elements.

For most spreading applications, it is desirable to counter-rotate the two dispensing elements in synchronism, as in the case of the embodiments of the invention wherein slinger members, or paddles, are mounted to the dispensing elements to aid in the ejection of granular fertilizer therefrom. Such synchronous counter-rotation is actually necessary where slinger members are used, as is a slinger member arrangement for each dispensing element which will prevent the slinger members on the two dispensing elements to pas through the overlapping portion of the rotation path of said elements, without any interference between any of the slinger members on one element, and any slinger member on the other element when said elements are synchronously counter-rotated. Accordingly, the means for rotating said dispensing elements in the spreader according to the invention is preferably a synchronous counter-rotating drive means.

A centrifugal spreader can be constructed in accordance with the instant invention, in which the fertilizer runs out of a hopper onto at least two approximately horizontally disposed, adjacent and oppositely rotating disk-like dispensing elements which have slinger paddles attached, with the slinger paddles of one disk being offset angularly from those of the adjacent disk.

The purpose of these slinger paddles is to increase the distance of fertilizer throw and hence the spreading width of the centrifugal spreader, and to improve the quality of the spreading pattern produced.

3,368,762 Patented Feb. 13, 1968 While in general, centrifugal spreaders having disk dispensing elements and slinger paddles attached thereto are known, in such prior art spreaders it is necessary to increase the rotation speed of the dispensing disks in order to increase the spreading pattern width. In addition to a relatively complex and consequently expensive design of the transmission used for driving such dispensing disks, these prior art spreading machines have the disadvantage that the increased peripheral speed of the dispensing disks at the area to which the fertilizer is fed, plus the stirring and positive-feed members used for bringing the fertilizer out of the hopper increase the percentage of fertilizer granules that are crushed and broken by these members, and an uneven spreading job frequently results when the disk speed is increased to effect a wider spread pattern. Further-more, considerable dust is produced by such prior art spreaders when spreading powdered types of fertilizers.

In the prior art, centrifugal spreaders are also known which have spinning disks which are offset from one another but are disposed in different planes, and in which the increase of spread pattern width is accomplished by slinger paddles which extend beyond the outer margin of the disk. In such spreader machines there is the disadvantage that the distances of throw of the fertilizer particles that are flung out by the slinger paddles are unequal because of the dilferent spacing of the spinning disks from the ground, so that an uneven spreading pattern results.

These disadvantages of prior art spreading machines are eliminated substantially in the centrifugal spreader of the invention because of the arrangement of the slinger paddle orbits wherein the orbits of the slinger paddles on the disk dispensing elements partially overlap and intersect. By this feature it is possible to arrange the slinger paddles to project beyond the outer margin of the dispensing disks, so that a greater spreading width is produced as a result of the greater circumferential speed. In this case, however, the peripheral speed in the area where the fertilizer is introduced onto the dispensing disks remains substantially the same.

Since it has proven advantageous for accurate spreading work, Le. a uniform spread pattern, to keep the free space between the centrifugal dispensing disks as small as possible, in accordance with the invention, the dispensing disks can be provided with gaps into which the slinger paddles and/or portions of the adjacent dispensing disk engage during the rotation of said disks. In this manner, the particles of the material being spread which slide directly ofi from the dispensing disks due to the rotation thereof, i.e., which are not caught by the slinger paddles of either disk, do not drop down between the disks, but are spread on the ground over a wide centralarea by the alternating action of the adjacent disks and slinger paddles. A wider spreading eifect can be achieved by providing the disks with cover surfaces underneath the gaps which seal off the gaps from beneath.

In the spreader of the instant invention, such gaps are provided in the form of cut-away portions on the periphery of each disk, said gaps being in effect clearance gaps which permit the passage of the slinger paddles on each disk through the overlap region of the disk rotation paths without interference between slinger paddles on the other disk. Each disk has a number of such peripheral clearance gaps equal to the number of slinger paddles on the other disk, with the clearance gaps on each disk being disposed with respect to the rotation center thereof in an angular arrangement which is substantially similar to the angular arrangement of the slinger paddles on the other disk with respect to its center of rotation. Thus, when the two disks are synchronously counter-rotated, there is no striking or contact between said disks or between their slinger 1 3 paddles or the slinger paddles on one disk and the other disk.

In a preferred embodiment of the invention, the slinger paddles are radially disposed with respect to the center of rotation of their respective disks. By providing means for selectively adjusting the radial position of the slinger paddles relative to the center of their respective disks, which are generally circular, it is possible to vary the spreading pattern width and hence to adapt the spreading machine of the invention to particular requirements, such as row plantings of pre-determined width.

It is therefore, an object of the invention to provide a spreader for dispensing granular materials such as mineral fertilizers.

Another object of the invention is to provide a spread er as aforesaid which accomplishes the dispensing of the granular material by centrifugal force action.

-A further object of the invention is to provide a spreader as aforesaid which is capable of producing a relatively unifor-m spread pattern.

A further object of the invention is to provide a spreader as aforesaid having means for selectively varying the width of the spreading pattern produced.

Still another object of the invention is to provide a spreader as aforesaid which accomplishes the spreading of granular fertilizer without any substantial grain breakage.

Other and further objects and advantages of the invention will become apparent from the following detailed description and accompanying drawings in which:

FIG. 1 is a schematic plan view of a centrifugal spreader according to a preferred embodiment of the invention.

FIG. 2 is a schematic plan view of a centrifugal spreader according to another embodiment of the invention.

FIG. 3 is a schematic plan view of a centrifugal spreader according to another and further embodiment of the invention.

FIG. 4 is a schematic plan view of a centrifugal spreader according to still another embodiment of the invention.

FIG. 5 is an elevation view, partly in section, of the centrifugal spreader of FIG. 4, as taken through the line A-B therein.

Referring now to FIG. 1, which schematically illustrates the esential features of a centrifugal spreader S for dispensing granular fertilizer materials in accordance with the invention, a first disk element 1 is disposed for rotation in a first path P and a second disk element 1 is dis posed for rotation in a second path P which is fixed in relation to the first path P and also preferably fixed in relation to a base (not shown) such as a vehicle platform which carries the spreader S. The paths P and P are partially overlapping and intersecting so as to provide a spreader S having an adjacently disposed pair of centrifugal dispensing elements 1 and 1' for producing a fertilizer spread pattern coverage which is substantially uniform and greater in width than could be provided by one of such dispensing elements 1 or 1' operating alone at the same rotation speed. i

The disks 1 and 1' are preferably circular, and are disposed for counter-rotation in approximately horizontal planes, preferably in the same horizontal plane. Any suitable conventional means (not shown) can be used to support the disks 1 and 1' for rotation in approximately horizontal co-planar paths P and P such as for example, by mounting the disks 1 and 1' on rotor shafts 21 journally supported by a base means B as in FIG. 5.

Any suitable conventional drive means (not shown) can be used for counter-rotating the disks 1 and 1' in synchronism, such as for example, a drive means sup ported by the base means B.

In the operation of the spreader S, the granular ferti lizer is introduced onto the upper surfaces of the disks 1 and 1' and it is spreadingly dispensed therefrom by centrifugal forces resulting from the rotation of said disks 1 and 1'. The fertilizer can be supplied to the disks 1 and 1 by any suitable conventional means, such as manual means, or by means of a hopper H, as in FIG. 5 which is disposed in overlying spaced-apart relation to said disks 1 and 1 for free-fall of the fertilizer onto said disks 1 and 1'.

To aid in the dispensing of fertilizer from the disks 1 and 1', each of said disks 1 and 1 are provided with at least one, and preferably a plurality of radially disposed slinger paddles 3 which are mounted to said disks 1 and 1 by any suitable conventional fastening means, such as for example, by screws 2.

The slinger paddles 3 are so arranged on their respective disks 1 and 1' so as to pass through the overlapping portion-of the rotation paths P and P without inter- 'ference or physical contact between any of the slinger paddles 3 on the disk 1 with either the disk 1' or any of the slinger paddles 3 on said disk 1', and so that there is no interference or physical contact between any of the slinger paddles 3 on the disk 1' and any portion of the disk 1.

Thus, as can be seen by the slinger paddles 3 arrangement of FIG. 1, the slinger paddles 3 which project beyond the peripheral boundaries of the disks 1 and 1', even though the outer extremities of said slinger paddles 3 travel in intersecting orbital paths 5 and 5, there is no interference or physical contact between element carried by the disk 1 and any element carried by the disk 1' when said disks 1 and 1' are counter-rotated in synchronism as indicated by the arrows 4 and 4 respectively.

In comparing the generally distinguishing features between the various embodiments of the invention, as represented by the spreaders S, S, S" and S of FIGS. 1, 2, 3 and 4 respectively, it will be apparent to the artisan that these several embodiments all utilize similar disk-like centrifugal dispensing elements, which are generally circular in peripheral shape, and that those dispensing elements, as represented by the disks 1 and 1', 6 and 6, 10 and 10', 14 and 14', in FIGS. 1, 2, 3, 4 (and also FIG. 5) respectively, are substantially co-planar. Furthermore, generally similar slinger paddles 3, 8 and 12 can be used in these several embodiments of the invention.

In the embodiment represented by FIG. 1, the diameter and spacing of the disks 1 and 1' are such in relation to the radial extent of the slinger paddles 3 that during rotation of the disks 1 and 1 there is no possibility that any slinger paddle 3 can contact an adjacent disk 1 or 1', and obviously, there is no contact between the disks 1 and 1' because of their circular shape and the fact that they rotate about axes passing through their geometrical centers.

Hence, in the spreader S of FIG. 1, the only potential interference is between the slinger paddles 3 of adjacent disks 1 and 1, this interference being eliminated by synchronous counter-rotation of said disks 1 and 1' and by using a compatible angular arrangement of said slinger paddles 3 so that when the disks 1 and 1' are synchronously counter-rotated, said paddles 3 in adjacent disks 1 and 1' pass between one another, with preferably symmetrical clearance distances between the slinger paddles 3 on the disk 1 and those on the disk 1.

In the embodiment represented by FIGS. 2, 4 and 5, there is no possibility of interference between the disks 6 and 6, or between the disks 14 and 14 because of their center spacing being greater than their diameters. However, in these particular embodiments, such as shown by FIG. 2, there is a potential interference between the slingcr paddles 8 on the disks 6 and 6, as well as between the slinger paddles 8 on the disk 6 and the disk 6, and conversely between the slinger paddles 8 on the disk 6' and the disk 6 itself, because the radial extension of said slinger paddles 8, i.e. the tips of the slinger paddles 8 are located at radii which are greater individually than the sum of the radius of their respective disks 6 or 6' and the radial clearance between said disks 6 and 6.

Substantially the same potential interference problem exists between the slinger paddles 8 and disks 14 and 14' of FIGS. 4 and 5.

In the embodiments of FIGS. 2, 4 and 5, this potential interference is avoided in accordance with the invention by synchronously counter-rotating the disks 6 and 6', 14 and 14, and by providing cut-away portions on the periphery of said disks 6, 6', 14, 14' to form clearance gaps 7 and 13 that accommodate the passage of the slinger members 8 on adjacent disks 6, 6, 14, 14 without interference or physical contact between any of the slinger paddles 8 and any disk 6, 6', 14, 14.

For example, in FIG. 2 each disk 6, 6 has a number of peripheral clearance gaps 7 equal to the number of slinger paddles 8 carried by its adjacent disk 6, 6. The clearance gaps 7 on each disk 6, 6 are disposed in an angular arrangement with respect to the center of rotation of said disk 6, 6' which is substantially similar to the angular arrangement of the slinger paddles 8 on the adjacent disk 6', 6 with respect to its center of rotation, so that when the disks 6 and 6' are synchronously counterrotated, the slinger paddles on each pass in engagement, but without any physical contact, into the gaps 7 of the other. Substantially the same gap 13 and slinger paddle 8 arrangement is used in the embodiment represented by FIGS. 4 and 5 for the same purpose.

Thus, the embodiments of FIGS. 2, 4 and 5 are substantially similar in construction, with the exception being in the case of the embodiment of FIGS. 4 and 5, that cup plate members 15 are disposed underneath each peripheral clearance gap 13 to centrifugally dispense fertilizer passing downward through said gaps 13 when the disks 14 and 14 are synchronously counter-rotated, each of said cup plate members 15 being fixedly attached to its corresopnding overlying disk 14, 14.

The cup plate members 15 are similar in construction to scoops, and are open in the outward radial directions of their respective disks 14, 14' to permit the free ejection of captured fertilizer by centrifugal action.

In the embodiment of the invention represented by FIG. 3, a somewhat different slinger paddle 12 and clearance gap 11 arrangement is presented. As can readily be noted, the disks 10 and 10 are center spaced closer than the sum of their radii, and while the slinger paddles 12 do not extend beyond the peripheral boundaries of said disks 10 and 10, the clearance gaps 11 are required and are thus provided as well as synchronous counter-rotation of the disks 10 and 10' in order to prevent interference between said disks 10 and 10'.

The disks 10 and 10' in FIG. 3 have a greater diameter than those in the previously described embodiment. To

this end, they are provided with gaps 11 having inside edges that are arcuately shaped. The slinger paddles 12 in this embodiment do not reach beyond the outer margin of the disks 10 and 10', while said disks 10 and 10' mesh with one another in a manner similar to that of gears when counter-rotated, but Without any physical contact between one another.

In the embodiment represented by FIG. 2, the disks 6 and 6 are provided with clearance gaps 7 into which the slinger paddles 8 of the adjacent disk 6, 6' in each case engage as said disks 6, 6' are counter-rotated. At the same time, the slinger paddles 8 are each provided with two additional spaced apart mounting holes 9, to provide a capability for adjusting their radial extension in either of two selected radial extension positions, so as to provide a capability of varying the width of the spread path.

In the embodiment represented by FIGS. 4 and 5, the clearance gaps 13 in the disks 14 and 14 are shaped similarly to the clearance gaps 7 in the spreader S of FIG. 2. The disks 14, however, are indented to produce the gaps 13, in such a manner that the plate member 15 surfaces are produced beneath said gaps 13. The disks 14 can be manufactured as by a stamping operation, so

as to produce integral cup plate members 15 and the gaps 13 without the need for any actual cutting away, as would conventionally be done to produce the gaps 13 in cases where the cup plate members 15 were welded onto the disks 14 and 14'.

The radial adjustment capability of the slinger paddles 8, can be further increased in accordance with the invention by providing not only additional holes 9 in said slinger paddles 8, but also by providing additional holes 16 in the disks 14 and 14, said holes 16 being arranged along radial lines on each of the disks 14 and 14. The provision of such additional holes 16 together with the holes 9 in the slinger paddles 8, makes possible a refinement in the adjustment of the spreading pattern width to meet specific individual requirements.

What is claimed is:

1. A spreader for granular material, which comprises a base means, a pair of centrifugal scattering members carried by said base means and disposed for synchronous rotation relative thereto, and means for introducing granular material from a supply thereof onto each of said scattering members to spreadingly dispense said granular material by centrifugal forces arising from the rotation of said scattering members, each of said scattering members including a disk and at least one slinger element mounted on said disk for movement therewith, both of said disks being generally circular and being disposed for counter-rotation about their respective geometrical centers, said slinger elements carried by each disk being disposed for extension into the path swept by the other disk, each disk having peripheral cut-away portions arranged to accommodate the extension of the slinger elements carried by the other disk without interference during synchronous counter-rotation of said disks, the sum of the maximum radial dimensions of both scattering members as measured from the rotation centers of their respective disks being greater than the distance between said disk rotation centers, whereby during the rotation of said scattering members, parts of one scattering member extend into the path swept by the other scattering member, the peripheral contours of said disks and said slinger elements being arranged to allow synchronous rotation of said scattering members without interference.

2. The spreader according to claim 1 wherein the sum of the radii of said disks exceeds the distance between their centers of rotation and each disk has peripheral cut-away portions arranged to accommodate the extension into the path swept by said disk of complementary peripheral portions of the other disk without interference during synchronous counter-rotation of said disks.

3. The spreader according to claim 1 including a cup plate member affixed to the underside of each disk for movement therewith at each peripheral cut-away portion thereof to aid in the centrifugal spreading of said granular material.

4. The spreader according to claim 1 wherein said slinger elements are adjustably mounted to their respective disks to accommodate positioning of said slinger elements at selected radial distances from their disk rotation centers.

5. The spreader according to claim 2 wherein the slinger elements associated with each disk are radially disposed and lie within the peripheral boundary thereof.

References Cited UNITED STATES PATENTS 1,770,707 7/1930 McDow 275-8 3,001,465 9/1961 Donelson 275-15 X FOREIGN PATENTS 733,935 7/ 1955 Great Britain.

ABRAHAM G. STONE, Primary Examiner. J. R. OAKS, Assistant Examiner. 

